DISCLAIMER: Use this at your own risk! It is entirely down to each user to update as needed!

Users of app_info.xml method: This method will not be supported by WCG in the future. Please check the prerequisites list below and use the new setup guide. This is much simpler, with no AMD/NVIDIA specific code and avoids a lot of issues we encountered in the past

1) Why run multiple GPU work units?
By default World Community Grid is setup to run a single GPU WU on your machine. This guide will show you how to get better performance from your GPU by running more than 1 WU at a time. This can increase the output of both your PPD (point per day) and the runtime per day. This is achieved by creating a file called app_config.xml to detail how to use your hardware

2) Prerequisites
Before creating the app_config.xml file you will need:

*NOTE* If you were using app_info.xml before:
Please hit "No new tasks" and complete your WU. Once your task list is clear, please remove the app_info.xml file and update BOINC to version 7.0.40 or above. Do not update before you clear the tasks as you may encounter problems submitting finished work units.

Login to the WCG website and check your project lists include HCC and that the option to do GPU work is ticked on the profile assigned to your computer.

3) Auto-setup utility for app_config.xml
The fastest way to setup the file is using m&m's easy to use utility. Enter your desired numbers and everything will be created for you in the right place. Remember to restart your BOINC Manager aftwerwards in order for the file to be read correctly:

Hello everybody, I did a utility to set all the settings required faster.
The utility works with Vista/7/8 and with the new app_config.xml (BOINC version 7.0.40 or above).

Basically, it creates the app_config.xml with all your settings.

Click to expand...

4) Manual setup guide for app_config.xml
If you would prefer to make all changes manually you can follow the steps listed below. (If you've already used the auto-setup in previous point, you can skip this entirely).

Alternatively if you prefer to manually edit your file the nextOpen notepad or other text editor and copy the following code into it:

max_concurrent: This specifies the maximum number of WU the app can run at a time. Best to set this to the number of total HCC1 WU your computer will be doing at a time.

gpu_usage: This specifies the % use of the GPU per WU. Set this according to how many WU you want to run per GPU.1 / Desired WU per GPU = gpu_usage

cpu_usage: This specifies the % use of CPU threads per GPU WU. The default value is 1, but if you want to run more GPU WU than you have CPU cores edit it accordingly.Total CPU Threads / Total GPU WU = cpu_usage

Check the event log (ctrl+shift+e) for any errors. I found that in switching from app_info it sometimes doesn't download any WU but once you hit the "update" button a few times it all looks normal. If you get an error about app_name not found in file, check the numbers you entered are correct and perhaps reset the project.

max_concurrent can be used to limit the HCC WU. For example if you have 8 CPU threads and want to use 2 for other projects you can set the value for HCC max_concurrent to 6.

5) Troubleshooting

How many WU to run?
Your mileage may vary, as factors like CPU speed and numer of threads have an impact on performance. The best way to determine what works best for you is to find out how long a single WU takes then see how much longer it takes to complete multiple WU. Below is a simple list for ballpark figures:
- Most NVIDIA: 2-3 WU
- AMD 6970: 4 WU
- AMD 7770: 3-4 WU
- AMD 79xx: 8-12 WU

Mixed/Multi GPU
If you're using mixed cards by default BOINC uses the best one, and in some cases may not use all your GPU even if they're the same. To use more than one GPU in the same machine go to the BOINC data folder (normally: C:\Program Data\BOINC) and look for file "cc_config.xml". If it doesn't exist, create it but the contents should have the following:

6) Old app_info method
This is for reference only. Not supported in future.

What is this?
ATI/AMD users will notice that by default their GPU isn't loaded to 100% and NVIDIA users may have GPU's that are capable of more compute work. This allows you to manually set how many work units you want to crunch simultaneously on your GPU.

How does it work?
You create a file called app_info.xml inside the project folder of your BOINC Data folder (normally: C:\Program Data\BOINC\Data\projects\www.worldcommunitygrid.org). The contents of this file will determine:
- How many GPU WU to run at a time
- Which WCG projects to run

If you're using mixed cards by default BOINC uses the best one, and in some cases may not use all your GPU even if they're the same. To use more than one GPU in the same machine go to the BOINC data folder (normally: C:\Program Data\BOINC) and look for file "cc_config.xml". If it doesn't exist, create it but the contents should have the following:

[Edited]Just be careful loading up the wu's. You only want to load the gpu to around 95%. If you load it to much you will start erroring out the wu's. Also make sure you have good case air flow as the card is going to steady be at 95 or so %. And as KieX stated use at your own risk.

10/21/2012 10:19:43 PM World Community Grid [error] App version returned from anonymous platform project; ignoring

Simply ignore it.

If you receive this error:

10/21/2012 10:19:43 PM World Community Grid [error] No application found for task: windows_intelx86 640 ; discarding

It indicates that you have not spell the name of the application in the app_info.xml correct or the application is missing in the BOINC\Data\projects\www.worldcommunitygrid.org map, if that's the case you can hit 'Reset project' under 'Projects' in the BOINC manager.

Just be careful loading up the wu's. You only want to load the gpu to around 95%. If you load it to much you will start erroring out the wu's. You just want to get the gpu to use it's idle time so you can maximize the crunching power. Also make sure you have good case air flow as the card is not going to get the break in between the wu's to cool down. It is going to steady be at 95 or so % no down time. And as Keix stated use at your own risk.

Just be careful loading up the wu's. You only want to load the gpu to around 95%. If you load it to much you will start erroring out the wu's. You just want to get the gpu to use it's idle time so you can maximize the crunching power. Also make sure you have good case air flow as the card is not going to get the break in between the wu's to cool down. It is going to steady be at 95 or so % no down time. And as Keix stated use at your own risk.

Click to expand...

It doesn't seem to be giving me a steady pattern, still loads, and unloads as before.. just loads higher each time. Will add your advice to the OP though.. that's a pretty good point regarding the errors and cooling.

Wondering if I set the count to .125 if I can run all 8 cores on gpu wu's?

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From all the posts I've seen, the maximum anyone used is 6 WU on a 7970. No idea if 8 will work or not, this is testing after all. But I'd recommend allowing a few hours in each setting to at least see if it gives any problems.

Wondering if I set the count to .125 if I can run all 8 cores on gpu wu's?

Click to expand...

When I was reading up on this last week there was a guy running 8 on a 7970 and he started getting errors. He had to back it down to 4. It was recommended to add 1 wu at a time until you get close to 95% load and stop there. Once you hit optimal and it takes sometime and patience and skill because you may have to start each wu manually, but you can get it to where one is starting right when another is finishing so there is no down time on the gpu. Also if you run more then on you can have it so there is one at 50% when the one is finishing and one is starting. I haven't tried it because my 6850's are already at 93% load with just one. But the 7850 is fair game as it is just over 80% load with one. When I get some time to play with it I will load that gpu up with more wu's.

When I was reading up on this last week there was a guy running 8 on a 7970 and he started getting errors. He had to back it down to 4. It was recommended to add 1 wu at a time until you get close to 95% load and stop there. Once you hit optimal and it takes sometime and patience and skill because you may have to start each wu manually, but you can get it to where one is starting right when another is finishing so there is no down time on the gpu. Also if you run more then on you can have it so there is one at 50% when the one is finishing and one is starting. I haven't tried it because my 6850's are already at 93% load with just one. But the 7850 is fair game as it is just over 80% load with one. When I get some time to play with it I will load that gpu up with more wu's.

Click to expand...

I'm peaking @87% load and 60C max temps so I can definitely fit in a 4th wu. The peak load% only lasts for 5-6 seconds and then it drops into the 70's due to the stagger on the wu's.

I think I can squeeze in a 5th wu without causing errors but I don't think I'll push it THAT hard...